Intracranial pressure (ICP) was measured in six patients following cardiopulmonary resuscitation (CPR). The causes of cardiac arrest were respiratory or circulatory problems and the primary intracranial pathology was not detected. The measurement of ICP started 3 to 10 h following CPR except one patient in whom it started on the day 7. Duration of ICP measurement ranged from 2 to 7 days. In five out of six patients, ICP persistently remained below 20 mmHg. In the remaining one patient, ICP elevation associated with seizure activity was observed and ICP ultimately increased to 57 mmHg. Among these, four patients died and two remained in a persistent vegetative state. These results suggest that ICP following CPR does not necessarily increase if the patient has no primary intracranial pathology or seizures.